What Is Insulation R-Value

What does the insulation’s R-Value mean?
Thermal resistance is the ability of a material to resist heat flow. That resistance is measured by an R-value. The greater the R-value, the more the insulation resists the movement of heat. A small percentage of newer houses are built with insulation that meets optimal standards but rarely are older homes up to par unless they have been upgraded with some newer type of insulation.

Minimum R-values recommendations for homes vary by climate and usually are affected by how a house is built and the type of heating system used. Here are a few rules of thumb:

• For mild climates, R-11 in the walls and floors and R-19 in ceilings below ventilated attics.
• For moderate climates, R-19 in the walls and floors and R-30 in ceilings below ventilated attics.
• For cold climates, R-19 in walls and under floors and R-38 to R-49 in ceilings below ventilated attic spaces.